device/usb/mojo/device_impl.cc - chromium/src - Git at Google

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "device/usb/mojo/device_impl.h"

 #include <stddef.h>

 #include <algorithm>
 #include <numeric>
 #include <utility>
 #include <vector>

 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/stl_util.h"
 #include "device/usb/mojo/type_converters.h"
 #include "device/usb/usb_descriptors.h"
 #include "device/usb/usb_device.h"
 #include "net/base/io_buffer.h"

 namespace device {
 namespace usb {

 namespace {

 using MojoTransferInCallback =
     mojo::Callback<void(TransferStatus, mojo::Array<uint8_t>)>;

 using MojoTransferOutCallback = mojo::Callback<void(TransferStatus)>;

 template <typename... Args>
 void CallMojoCallback(scoped_ptr<mojo::Callback<void(Args...)>> callback,
                       Args... args) {
   callback->Run(args...);
 }

 // Generic wrapper to convert a Mojo callback to something we can rebind and
 // pass around. This is only usable for callbacks with no move-only arguments.
 template <typename... Args>
 base::Callback<void(Args...)> WrapMojoCallback(
     const mojo::Callback<void(Args...)>& callback) {
   // mojo::Callback is not thread safe. By wrapping |callback| in a scoped_ptr
   // we guarantee that it will be freed when CallMojoCallback is run and not
   // retained until the base::Callback is destroyed, which could happen on any
   // thread. This pattern is also used below in places where this generic
   // wrapper is not used.
   auto callback_ptr =
       make_scoped_ptr(new mojo::Callback<void(Args...)>(callback));
   return base::Bind(&CallMojoCallback<Args...>, base::Passed(&callback_ptr));
 }

 scoped_refptr<net::IOBuffer> CreateTransferBuffer(size_t size) {
   scoped_refptr<net::IOBuffer> buffer = new net::IOBuffer(
       std::max(static_cast<size_t>(1u), static_cast<size_t>(size)));
   return buffer;
 }

 void OnTransferIn(scoped_ptr<MojoTransferInCallback> callback,
                   UsbTransferStatus status,
                   scoped_refptr<net::IOBuffer> buffer,
                   size_t buffer_size) {
   mojo::Array<uint8_t> data;
   if (buffer) {
     // TODO(rockot/reillyg): We should change UsbDeviceHandle to use a
     // std::vector<uint8_t> instead of net::IOBuffer. Then we could move
     // instead of copy.
     std::vector<uint8_t> bytes(buffer_size);
     std::copy(buffer->data(), buffer->data() + buffer_size, bytes.begin());
     data.Swap(&bytes);
   }
   callback->Run(mojo::ConvertTo<TransferStatus>(status), std::move(data));
 }

 void OnTransferOut(scoped_ptr<MojoTransferOutCallback> callback,
                    UsbTransferStatus status,
                    scoped_refptr<net::IOBuffer> buffer,
                    size_t buffer_size) {
   callback->Run(mojo::ConvertTo<TransferStatus>(status));
 }

 mojo::Array<IsochronousPacketPtr> BuildIsochronousPacketArray(
     mojo::Array<uint32_t> packet_lengths,
     TransferStatus status) {
   mojo::Array<IsochronousPacketPtr> packets(packet_lengths.size());
   for (size_t i = 0; i < packet_lengths.size(); ++i) {
     packets[i] = IsochronousPacket::New();
     packets[i]->length = packet_lengths[i];
     packets[i]->status = status;
   }
   return packets;
 }

 void OnIsochronousTransferIn(
     scoped_ptr<Device::IsochronousTransferInCallback> callback,
     scoped_refptr<net::IOBuffer> buffer,
     const std::vector<UsbDeviceHandle::IsochronousPacket>& packets) {
   mojo::Array<uint8_t> data;
   if (buffer) {
     // TODO(rockot/reillyg): We should change UsbDeviceHandle to use a
     // std::vector<uint8_t> instead of net::IOBuffer. Then we could move
     // instead of copy.
     uint32_t buffer_size =
         std::accumulate(packets.begin(), packets.end(), 0u,
                         [](const uint32_t& a,
                            const UsbDeviceHandle::IsochronousPacket& packet) {
                           return a + packet.length;
                         });
     std::vector<uint8_t> bytes(buffer_size);
     std::copy(buffer->data(), buffer->data() + buffer_size, bytes.begin());
     data.Swap(&bytes);
   }
   callback->Run(std::move(data),
                 mojo::Array<IsochronousPacketPtr>::From(packets));
 }

 void OnIsochronousTransferOut(
     scoped_ptr<Device::IsochronousTransferOutCallback> callback,
     scoped_refptr<net::IOBuffer> buffer,
     const std::vector<UsbDeviceHandle::IsochronousPacket>& packets) {
   callback->Run(mojo::Array<IsochronousPacketPtr>::From(packets));
 }

 }  // namespace

 DeviceImpl::DeviceImpl(scoped_refptr<UsbDevice> device,
                        DeviceInfoPtr device_info,
                        base::WeakPtr<PermissionProvider> permission_provider,
                        mojo::InterfaceRequest<Device> request)
     : device_(device),
       device_info_(std::move(device_info)),
       permission_provider_(permission_provider),
       observer_(this),
       binding_(this, std::move(request)),
       weak_factory_(this) {
   DCHECK(device_);
   // This object owns itself and will be destroyed if,
   //  * the device is disconnected or
   //  * the message pipe it is bound to is closed
   observer_.Add(device_.get());
   binding_.set_connection_error_handler([this]() { delete this; });
 }

 DeviceImpl::~DeviceImpl() {
   CloseHandle();
 }

 void DeviceImpl::CloseHandle() {
   if (device_handle_)
     device_handle_->Close();
   device_handle_ = nullptr;
 }

 bool DeviceImpl::HasControlTransferPermission(
     ControlTransferRecipient recipient,
     uint16_t index) {
   DCHECK(device_handle_);
   const UsbConfigDescriptor* config = device_->GetActiveConfiguration();

   if (!permission_provider_)
     return false;

   if (recipient == ControlTransferRecipient::INTERFACE ||
       recipient == ControlTransferRecipient::ENDPOINT) {
     if (!config)
       return false;

     const UsbInterfaceDescriptor* interface = nullptr;
     if (recipient == ControlTransferRecipient::ENDPOINT) {
       interface = device_handle_->FindInterfaceByEndpoint(index & 0xff);
     } else {
       auto interface_it =
           std::find_if(config->interfaces.begin(), config->interfaces.end(),
                        [index](const UsbInterfaceDescriptor& this_iface) {
                          return this_iface.interface_number == (index & 0xff);
                        });
       if (interface_it != config->interfaces.end())
         interface = &*interface_it;
     }
     if (interface == nullptr)
       return false;

     return permission_provider_->HasFunctionPermission(
         interface->first_interface, config->configuration_value, *device_info_);
   } else if (config) {
     return permission_provider_->HasConfigurationPermission(
         config->configuration_value, *device_info_);
   } else {
     // Client must already have device permission to have gotten this far.
     return true;
   }
 }

 void DeviceImpl::OnOpen(const OpenCallback& callback,
                         scoped_refptr<UsbDeviceHandle> handle) {
   device_handle_ = handle;
   callback.Run(handle ? OpenDeviceError::OK : OpenDeviceError::ACCESS_DENIED);
 }

 void DeviceImpl::GetDeviceInfo(const GetDeviceInfoCallback& callback) {
   const UsbConfigDescriptor* config = device_->GetActiveConfiguration();
   device_info_->active_configuration = config ? config->configuration_value : 0;
   callback.Run(device_info_->Clone());
 }

 void DeviceImpl::Open(const OpenCallback& callback) {
   if (device_handle_)
     callback.Run(OpenDeviceError::ALREADY_OPEN);
   else
     device_->Open(
         base::Bind(&DeviceImpl::OnOpen, weak_factory_.GetWeakPtr(), callback));
 }

 void DeviceImpl::Close(const CloseCallback& callback) {
   CloseHandle();
   callback.Run();
 }

 void DeviceImpl::SetConfiguration(uint8_t value,
                                   const SetConfigurationCallback& callback) {
   if (!device_handle_) {
     callback.Run(false);
     return;
   }

   if (permission_provider_ &&
       permission_provider_->HasConfigurationPermission(value, *device_info_)) {
     device_handle_->SetConfiguration(value, WrapMojoCallback(callback));
   } else {
     callback.Run(false);
   }
 }

 void DeviceImpl::ClaimInterface(uint8_t interface_number,
                                 const ClaimInterfaceCallback& callback) {
   if (!device_handle_) {
     callback.Run(false);
     return;
   }

   const UsbConfigDescriptor* config = device_->GetActiveConfiguration();
   if (!config) {
     callback.Run(false);
     return;
   }

   auto interface_it =
       std::find_if(config->interfaces.begin(), config->interfaces.end(),
                    [interface_number](const UsbInterfaceDescriptor& interface) {
                      return interface.interface_number == interface_number;
                    });
   if (interface_it == config->interfaces.end()) {
     callback.Run(false);
     return;
   }

   if (permission_provider_ &&
       permission_provider_->HasFunctionPermission(interface_it->first_interface,
                                                   config->configuration_value,
                                                   *device_info_)) {
     device_handle_->ClaimInterface(interface_number,
                                    WrapMojoCallback(callback));
   } else {
     callback.Run(false);
   }
 }

 void DeviceImpl::ReleaseInterface(uint8_t interface_number,
                                   const ReleaseInterfaceCallback& callback) {
   if (!device_handle_) {
     callback.Run(false);
     return;
   }

   device_handle_->ReleaseInterface(interface_number,
                                    WrapMojoCallback(callback));
 }

 void DeviceImpl::SetInterfaceAlternateSetting(
     uint8_t interface_number,
     uint8_t alternate_setting,
     const SetInterfaceAlternateSettingCallback& callback) {
   if (!device_handle_) {
     callback.Run(false);
     return;
   }

   device_handle_->SetInterfaceAlternateSetting(
       interface_number, alternate_setting, WrapMojoCallback(callback));
 }

 void DeviceImpl::Reset(const ResetCallback& callback) {
   if (!device_handle_) {
     callback.Run(false);
     return;
   }

   device_handle_->ResetDevice(WrapMojoCallback(callback));
 }

 void DeviceImpl::ClearHalt(uint8_t endpoint,
                            const ClearHaltCallback& callback) {
   if (!device_handle_) {
     callback.Run(false);
     return;
   }

   device_handle_->ClearHalt(endpoint, WrapMojoCallback(callback));
 }

 void DeviceImpl::ControlTransferIn(ControlTransferParamsPtr params,
                                    uint32_t length,
                                    uint32_t timeout,
                                    const ControlTransferInCallback& callback) {
   if (!device_handle_) {
     callback.Run(TransferStatus::TRANSFER_ERROR, mojo::Array<uint8_t>());
     return;
   }

   if (HasControlTransferPermission(params->recipient, params->index)) {
     scoped_refptr<net::IOBuffer> buffer = CreateTransferBuffer(length);
     auto callback_ptr =
         make_scoped_ptr(new ControlTransferInCallback(callback));
     device_handle_->ControlTransfer(
         USB_DIRECTION_INBOUND,
         mojo::ConvertTo<UsbDeviceHandle::TransferRequestType>(params->type),
         mojo::ConvertTo<UsbDeviceHandle::TransferRecipient>(params->recipient),
         params->request, params->value, params->index, buffer, length, timeout,
         base::Bind(&OnTransferIn, base::Passed(&callback_ptr)));
   } else {
     mojo::Array<uint8_t> data;
     callback.Run(TransferStatus::PERMISSION_DENIED, std::move(data));
   }
 }

 void DeviceImpl::ControlTransferOut(
     ControlTransferParamsPtr params,
     mojo::Array<uint8_t> data,
     uint32_t timeout,
     const ControlTransferOutCallback& callback) {
   if (!device_handle_) {
     callback.Run(TransferStatus::TRANSFER_ERROR);
     return;
   }

   if (HasControlTransferPermission(params->recipient, params->index)) {
     scoped_refptr<net::IOBuffer> buffer = CreateTransferBuffer(data.size());
     const std::vector<uint8_t>& storage = data.storage();
     std::copy(storage.begin(), storage.end(), buffer->data());
     auto callback_ptr =
         make_scoped_ptr(new ControlTransferOutCallback(callback));
     device_handle_->ControlTransfer(
         USB_DIRECTION_OUTBOUND,
         mojo::ConvertTo<UsbDeviceHandle::TransferRequestType>(params->type),
         mojo::ConvertTo<UsbDeviceHandle::TransferRecipient>(params->recipient),
         params->request, params->value, params->index, buffer, data.size(),
         timeout, base::Bind(&OnTransferOut, base::Passed(&callback_ptr)));
   } else {
     callback.Run(TransferStatus::PERMISSION_DENIED);
   }
 }

 void DeviceImpl::GenericTransferIn(uint8_t endpoint_number,
                                    uint32_t length,
                                    uint32_t timeout,
                                    const GenericTransferInCallback& callback) {
   if (!device_handle_) {
     callback.Run(TransferStatus::TRANSFER_ERROR, mojo::Array<uint8_t>());
     return;
   }

   auto callback_ptr = make_scoped_ptr(new GenericTransferInCallback(callback));
   uint8_t endpoint_address = endpoint_number | 0x80;
   scoped_refptr<net::IOBuffer> buffer = CreateTransferBuffer(length);
   device_handle_->GenericTransfer(
       USB_DIRECTION_INBOUND, endpoint_address, buffer, length, timeout,
       base::Bind(&OnTransferIn, base::Passed(&callback_ptr)));
 }

 void DeviceImpl::GenericTransferOut(
     uint8_t endpoint_number,
     mojo::Array<uint8_t> data,
     uint32_t timeout,
     const GenericTransferOutCallback& callback) {
   if (!device_handle_) {
     callback.Run(TransferStatus::TRANSFER_ERROR);
     return;
   }

   auto callback_ptr = make_scoped_ptr(new GenericTransferOutCallback(callback));
   uint8_t endpoint_address = endpoint_number;
   scoped_refptr<net::IOBuffer> buffer = CreateTransferBuffer(data.size());
   const std::vector<uint8_t>& storage = data.storage();
   std::copy(storage.begin(), storage.end(), buffer->data());
   device_handle_->GenericTransfer(
       USB_DIRECTION_OUTBOUND, endpoint_address, buffer, data.size(), timeout,
       base::Bind(&OnTransferOut, base::Passed(&callback_ptr)));
 }

 void DeviceImpl::IsochronousTransferIn(
     uint8_t endpoint_number,
     mojo::Array<uint32_t> packet_lengths,
     uint32_t timeout,
     const IsochronousTransferInCallback& callback) {
   if (!device_handle_) {
     callback.Run(mojo::Array<uint8_t>(),
                  BuildIsochronousPacketArray(std::move(packet_lengths),
                                              TransferStatus::TRANSFER_ERROR));
     return;
   }

   auto callback_ptr =
       make_scoped_ptr(new IsochronousTransferInCallback(callback));
   uint8_t endpoint_address = endpoint_number | 0x80;
   device_handle_->IsochronousTransferIn(
       endpoint_address, packet_lengths.storage(), timeout,
       base::Bind(&OnIsochronousTransferIn, base::Passed(&callback_ptr)));
 }

 void DeviceImpl::IsochronousTransferOut(
     uint8_t endpoint_number,
     mojo::Array<uint8_t> data,
     mojo::Array<uint32_t> packet_lengths,
     uint32_t timeout,
     const IsochronousTransferOutCallback& callback) {
   if (!device_handle_) {
     callback.Run(BuildIsochronousPacketArray(std::move(packet_lengths),
                                              TransferStatus::TRANSFER_ERROR));
     return;
   }

   auto callback_ptr =
       make_scoped_ptr(new IsochronousTransferOutCallback(callback));
   uint8_t endpoint_address = endpoint_number;
   scoped_refptr<net::IOBuffer> buffer = CreateTransferBuffer(data.size());
   {
     const std::vector<uint8_t>& storage = data.storage();
     std::copy(storage.begin(), storage.end(), buffer->data());
   }
   device_handle_->IsochronousTransferOut(
       endpoint_address, buffer, packet_lengths.storage(), timeout,
       base::Bind(&OnIsochronousTransferOut, base::Passed(&callback_ptr)));
 }

 void DeviceImpl::OnDeviceRemoved(scoped_refptr<UsbDevice> device) {
   DCHECK_EQ(device_, device);
   delete this;
 }

 }  // namespace usb
 }  // namespace device
	// Copyright 2015 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "device/usb/mojo/device_impl.h"

	#include <stddef.h>

	#include <algorithm>
	#include <numeric>
	#include <utility>
	#include <vector>

	#include "base/bind.h"
	#include "base/callback.h"
	#include "base/stl_util.h"
	#include "device/usb/mojo/type_converters.h"
	#include "device/usb/usb_descriptors.h"
	#include "device/usb/usb_device.h"
	#include "net/base/io_buffer.h"

	namespace device {
	namespace usb {

	namespace {

	using MojoTransferInCallback =
	mojo::Callback<void(TransferStatus, mojo::Array<uint8_t>)>;

	using MojoTransferOutCallback = mojo::Callback<void(TransferStatus)>;

	template <typename... Args>
	void CallMojoCallback(scoped_ptr<mojo::Callback<void(Args...)>> callback,
	Args... args) {
	callback->Run(args...);
	}

	// Generic wrapper to convert a Mojo callback to something we can rebind and
	// pass around. This is only usable for callbacks with no move-only arguments.
	template <typename... Args>
	base::Callback<void(Args...)> WrapMojoCallback(
	const mojo::Callback<void(Args...)>& callback) {
	// mojo::Callback is not thread safe. By wrapping \|callback\| in a scoped_ptr
	// we guarantee that it will be freed when CallMojoCallback is run and not
	// retained until the base::Callback is destroyed, which could happen on any
	// thread. This pattern is also used below in places where this generic
	// wrapper is not used.
	auto callback_ptr =
	make_scoped_ptr(new mojo::Callback<void(Args...)>(callback));
	return base::Bind(&CallMojoCallback<Args...>, base::Passed(&callback_ptr));
	}

	scoped_refptr<net::IOBuffer> CreateTransferBuffer(size_t size) {
	scoped_refptr<net::IOBuffer> buffer = new net::IOBuffer(
	std::max(static_cast<size_t>(1u), static_cast<size_t>(size)));
	return buffer;
	}

	void OnTransferIn(scoped_ptr<MojoTransferInCallback> callback,
	UsbTransferStatus status,
	scoped_refptr<net::IOBuffer> buffer,
	size_t buffer_size) {
	mojo::Array<uint8_t> data;
	if (buffer) {
	// TODO(rockot/reillyg): We should change UsbDeviceHandle to use a
	// std::vector<uint8_t> instead of net::IOBuffer. Then we could move
	// instead of copy.
	std::vector<uint8_t> bytes(buffer_size);
	std::copy(buffer->data(), buffer->data() + buffer_size, bytes.begin());
	data.Swap(&bytes);
	}
	callback->Run(mojo::ConvertTo<TransferStatus>(status), std::move(data));
	}

	void OnTransferOut(scoped_ptr<MojoTransferOutCallback> callback,
	UsbTransferStatus status,
	scoped_refptr<net::IOBuffer> buffer,
	size_t buffer_size) {
	callback->Run(mojo::ConvertTo<TransferStatus>(status));
	}

	mojo::Array<IsochronousPacketPtr> BuildIsochronousPacketArray(
	mojo::Array<uint32_t> packet_lengths,
	TransferStatus status) {
	mojo::Array<IsochronousPacketPtr> packets(packet_lengths.size());
	for (size_t i = 0; i < packet_lengths.size(); ++i) {
	packets[i] = IsochronousPacket::New();
	packets[i]->length = packet_lengths[i];
	packets[i]->status = status;
	}
	return packets;
	}

	void OnIsochronousTransferIn(
	scoped_ptr<Device::IsochronousTransferInCallback> callback,
	scoped_refptr<net::IOBuffer> buffer,
	const std::vector<UsbDeviceHandle::IsochronousPacket>& packets) {
	mojo::Array<uint8_t> data;
	if (buffer) {
	// TODO(rockot/reillyg): We should change UsbDeviceHandle to use a
	// std::vector<uint8_t> instead of net::IOBuffer. Then we could move
	// instead of copy.
	uint32_t buffer_size =
	std::accumulate(packets.begin(), packets.end(), 0u,
	[](const uint32_t& a,
	const UsbDeviceHandle::IsochronousPacket& packet) {
	return a + packet.length;
	});
	std::vector<uint8_t> bytes(buffer_size);
	std::copy(buffer->data(), buffer->data() + buffer_size, bytes.begin());
	data.Swap(&bytes);
	}
	callback->Run(std::move(data),
	mojo::Array<IsochronousPacketPtr>::From(packets));
	}

	void OnIsochronousTransferOut(
	scoped_ptr<Device::IsochronousTransferOutCallback> callback,
	scoped_refptr<net::IOBuffer> buffer,
	const std::vector<UsbDeviceHandle::IsochronousPacket>& packets) {
	callback->Run(mojo::Array<IsochronousPacketPtr>::From(packets));
	}

	} // namespace

	DeviceImpl::DeviceImpl(scoped_refptr<UsbDevice> device,
	DeviceInfoPtr device_info,
	base::WeakPtr<PermissionProvider> permission_provider,
	mojo::InterfaceRequest<Device> request)
	: device_(device),
	device_info_(std::move(device_info)),
	permission_provider_(permission_provider),
	observer_(this),
	binding_(this, std::move(request)),
	weak_factory_(this) {
	DCHECK(device_);
	// This object owns itself and will be destroyed if,
	// * the device is disconnected or
	// * the message pipe it is bound to is closed
	observer_.Add(device_.get());
	binding_.set_connection_error_handler([this]() { delete this; });
	}

	DeviceImpl::~DeviceImpl() {
	CloseHandle();
	}

	void DeviceImpl::CloseHandle() {
	if (device_handle_)
	device_handle_->Close();
	device_handle_ = nullptr;
	}

	bool DeviceImpl::HasControlTransferPermission(
	ControlTransferRecipient recipient,
	uint16_t index) {
	DCHECK(device_handle_);
	const UsbConfigDescriptor* config = device_->GetActiveConfiguration();

	if (!permission_provider_)
	return false;

	if (recipient == ControlTransferRecipient::INTERFACE \|\|
	recipient == ControlTransferRecipient::ENDPOINT) {
	if (!config)
	return false;

	const UsbInterfaceDescriptor* interface = nullptr;
	if (recipient == ControlTransferRecipient::ENDPOINT) {
	interface = device_handle_->FindInterfaceByEndpoint(index & 0xff);
	} else {
	auto interface_it =
	std::find_if(config->interfaces.begin(), config->interfaces.end(),
	[index](const UsbInterfaceDescriptor& this_iface) {
	return this_iface.interface_number == (index & 0xff);
	});
	if (interface_it != config->interfaces.end())
	interface = &*interface_it;
	}
	if (interface == nullptr)
	return false;

	return permission_provider_->HasFunctionPermission(
	interface->first_interface, config->configuration_value, *device_info_);
	} else if (config) {
	return permission_provider_->HasConfigurationPermission(
	config->configuration_value, *device_info_);
	} else {
	// Client must already have device permission to have gotten this far.
	return true;
	}
	}

	void DeviceImpl::OnOpen(const OpenCallback& callback,
	scoped_refptr<UsbDeviceHandle> handle) {
	device_handle_ = handle;
	callback.Run(handle ? OpenDeviceError::OK : OpenDeviceError::ACCESS_DENIED);
	}

	void DeviceImpl::GetDeviceInfo(const GetDeviceInfoCallback& callback) {
	const UsbConfigDescriptor* config = device_->GetActiveConfiguration();
	device_info_->active_configuration = config ? config->configuration_value : 0;
	callback.Run(device_info_->Clone());
	}

	void DeviceImpl::Open(const OpenCallback& callback) {
	if (device_handle_)
	callback.Run(OpenDeviceError::ALREADY_OPEN);
	else
	device_->Open(
	base::Bind(&DeviceImpl::OnOpen, weak_factory_.GetWeakPtr(), callback));
	}

	void DeviceImpl::Close(const CloseCallback& callback) {
	CloseHandle();
	callback.Run();
	}

	void DeviceImpl::SetConfiguration(uint8_t value,
	const SetConfigurationCallback& callback) {
	if (!device_handle_) {
	callback.Run(false);
	return;
	}

	if (permission_provider_ &&
	permission_provider_->HasConfigurationPermission(value, *device_info_)) {
	device_handle_->SetConfiguration(value, WrapMojoCallback(callback));
	} else {
	callback.Run(false);
	}
	}

	void DeviceImpl::ClaimInterface(uint8_t interface_number,
	const ClaimInterfaceCallback& callback) {
	if (!device_handle_) {
	callback.Run(false);
	return;
	}

	const UsbConfigDescriptor* config = device_->GetActiveConfiguration();
	if (!config) {
	callback.Run(false);
	return;
	}

	auto interface_it =
	std::find_if(config->interfaces.begin(), config->interfaces.end(),
	[interface_number](const UsbInterfaceDescriptor& interface) {
	return interface.interface_number == interface_number;
	});
	if (interface_it == config->interfaces.end()) {
	callback.Run(false);
	return;
	}

	if (permission_provider_ &&
	permission_provider_->HasFunctionPermission(interface_it->first_interface,
	config->configuration_value,
	*device_info_)) {
	device_handle_->ClaimInterface(interface_number,
	WrapMojoCallback(callback));
	} else {
	callback.Run(false);
	}
	}

	void DeviceImpl::ReleaseInterface(uint8_t interface_number,
	const ReleaseInterfaceCallback& callback) {
	if (!device_handle_) {
	callback.Run(false);
	return;
	}

	device_handle_->ReleaseInterface(interface_number,
	WrapMojoCallback(callback));
	}

	void DeviceImpl::SetInterfaceAlternateSetting(
	uint8_t interface_number,
	uint8_t alternate_setting,
	const SetInterfaceAlternateSettingCallback& callback) {
	if (!device_handle_) {
	callback.Run(false);
	return;
	}

	device_handle_->SetInterfaceAlternateSetting(
	interface_number, alternate_setting, WrapMojoCallback(callback));
	}

	void DeviceImpl::Reset(const ResetCallback& callback) {
	if (!device_handle_) {
	callback.Run(false);
	return;
	}

	device_handle_->ResetDevice(WrapMojoCallback(callback));
	}

	void DeviceImpl::ClearHalt(uint8_t endpoint,
	const ClearHaltCallback& callback) {
	if (!device_handle_) {
	callback.Run(false);
	return;
	}

	device_handle_->ClearHalt(endpoint, WrapMojoCallback(callback));
	}

	void DeviceImpl::ControlTransferIn(ControlTransferParamsPtr params,
	uint32_t length,
	uint32_t timeout,
	const ControlTransferInCallback& callback) {
	if (!device_handle_) {
	callback.Run(TransferStatus::TRANSFER_ERROR, mojo::Array<uint8_t>());
	return;
	}

	if (HasControlTransferPermission(params->recipient, params->index)) {
	scoped_refptr<net::IOBuffer> buffer = CreateTransferBuffer(length);
	auto callback_ptr =
	make_scoped_ptr(new ControlTransferInCallback(callback));
	device_handle_->ControlTransfer(
	USB_DIRECTION_INBOUND,
	mojo::ConvertTo<UsbDeviceHandle::TransferRequestType>(params->type),
	mojo::ConvertTo<UsbDeviceHandle::TransferRecipient>(params->recipient),
	params->request, params->value, params->index, buffer, length, timeout,
	base::Bind(&OnTransferIn, base::Passed(&callback_ptr)));
	} else {
	mojo::Array<uint8_t> data;
	callback.Run(TransferStatus::PERMISSION_DENIED, std::move(data));
	}
	}

	void DeviceImpl::ControlTransferOut(
	ControlTransferParamsPtr params,
	mojo::Array<uint8_t> data,
	uint32_t timeout,
	const ControlTransferOutCallback& callback) {
	if (!device_handle_) {
	callback.Run(TransferStatus::TRANSFER_ERROR);
	return;
	}

	if (HasControlTransferPermission(params->recipient, params->index)) {
	scoped_refptr<net::IOBuffer> buffer = CreateTransferBuffer(data.size());
	const std::vector<uint8_t>& storage = data.storage();
	std::copy(storage.begin(), storage.end(), buffer->data());
	auto callback_ptr =
	make_scoped_ptr(new ControlTransferOutCallback(callback));
	device_handle_->ControlTransfer(
	USB_DIRECTION_OUTBOUND,
	mojo::ConvertTo<UsbDeviceHandle::TransferRequestType>(params->type),
	mojo::ConvertTo<UsbDeviceHandle::TransferRecipient>(params->recipient),
	params->request, params->value, params->index, buffer, data.size(),
	timeout, base::Bind(&OnTransferOut, base::Passed(&callback_ptr)));
	} else {
	callback.Run(TransferStatus::PERMISSION_DENIED);
	}
	}

	void DeviceImpl::GenericTransferIn(uint8_t endpoint_number,
	uint32_t length,
	uint32_t timeout,
	const GenericTransferInCallback& callback) {
	if (!device_handle_) {
	callback.Run(TransferStatus::TRANSFER_ERROR, mojo::Array<uint8_t>());
	return;
	}

	auto callback_ptr = make_scoped_ptr(new GenericTransferInCallback(callback));
	uint8_t endpoint_address = endpoint_number \| 0x80;
	scoped_refptr<net::IOBuffer> buffer = CreateTransferBuffer(length);
	device_handle_->GenericTransfer(
	USB_DIRECTION_INBOUND, endpoint_address, buffer, length, timeout,
	base::Bind(&OnTransferIn, base::Passed(&callback_ptr)));
	}

	void DeviceImpl::GenericTransferOut(
	uint8_t endpoint_number,
	mojo::Array<uint8_t> data,
	uint32_t timeout,
	const GenericTransferOutCallback& callback) {
	if (!device_handle_) {
	callback.Run(TransferStatus::TRANSFER_ERROR);
	return;
	}

	auto callback_ptr = make_scoped_ptr(new GenericTransferOutCallback(callback));
	uint8_t endpoint_address = endpoint_number;
	scoped_refptr<net::IOBuffer> buffer = CreateTransferBuffer(data.size());
	const std::vector<uint8_t>& storage = data.storage();
	std::copy(storage.begin(), storage.end(), buffer->data());
	device_handle_->GenericTransfer(
	USB_DIRECTION_OUTBOUND, endpoint_address, buffer, data.size(), timeout,
	base::Bind(&OnTransferOut, base::Passed(&callback_ptr)));
	}

	void DeviceImpl::IsochronousTransferIn(
	uint8_t endpoint_number,
	mojo::Array<uint32_t> packet_lengths,
	uint32_t timeout,
	const IsochronousTransferInCallback& callback) {
	if (!device_handle_) {
	callback.Run(mojo::Array<uint8_t>(),
	BuildIsochronousPacketArray(std::move(packet_lengths),
	TransferStatus::TRANSFER_ERROR));
	return;
	}

	auto callback_ptr =
	make_scoped_ptr(new IsochronousTransferInCallback(callback));
	uint8_t endpoint_address = endpoint_number \| 0x80;
	device_handle_->IsochronousTransferIn(
	endpoint_address, packet_lengths.storage(), timeout,
	base::Bind(&OnIsochronousTransferIn, base::Passed(&callback_ptr)));
	}

	void DeviceImpl::IsochronousTransferOut(
	uint8_t endpoint_number,
	mojo::Array<uint8_t> data,
	mojo::Array<uint32_t> packet_lengths,
	uint32_t timeout,
	const IsochronousTransferOutCallback& callback) {
	if (!device_handle_) {
	callback.Run(BuildIsochronousPacketArray(std::move(packet_lengths),
	TransferStatus::TRANSFER_ERROR));
	return;
	}

	auto callback_ptr =
	make_scoped_ptr(new IsochronousTransferOutCallback(callback));
	uint8_t endpoint_address = endpoint_number;
	scoped_refptr<net::IOBuffer> buffer = CreateTransferBuffer(data.size());
	{
	const std::vector<uint8_t>& storage = data.storage();
	std::copy(storage.begin(), storage.end(), buffer->data());
	}
	device_handle_->IsochronousTransferOut(
	endpoint_address, buffer, packet_lengths.storage(), timeout,
	base::Bind(&OnIsochronousTransferOut, base::Passed(&callback_ptr)));
	}

	void DeviceImpl::OnDeviceRemoved(scoped_refptr<UsbDevice> device) {
	DCHECK_EQ(device_, device);
	delete this;
	}

	} // namespace usb
	} // namespace device